Omnidirectional photodetector

Abstract

An omnidirectional photodetector has a prism and a light-detecting device. The prism has a cylindrical columnar body and a conical member disposed on an end of the columnar body and having a cross-sectional area that is progressively smaller toward a tip end of the conical member. The prism is made of a light-transmissive synthetic resin. When the omnidirectional photodetector is in use, the conical member is positioned above the columnar body and has its axis oriented vertically. The conical member has a conical surface as an outer circumferential surface thereof providing a reflecting surface for reflecting a light beam applied from an external source to the conical surface into the columnar body and downwardly toward the lower end of the columnar body.

1 . An omnidirectional photodetector comprising: 
 a prism having a columnar body and a conical member disposed on an end of said columnar body and having a cross-sectional area that is progressively smaller toward a tip end of said conical member, said conical member having a conical surface as an outer circumferential surface thereof providing a reflecting surface for reflecting a light beam applied from an external source to said conical surface into said columnar body; and    a light-detecting device disposed at an opposite end of said columnar body, for detecting the light beam reflected by said reflecting surface and guided through said columnar body.    
   
   
       2 . The omnidirectional photodetector according to  claim 1 , further comprising: 
 a condenser lens disposed between said opposite end of said columnar body and said light-detecting device.    
   
   
       3 . The omnidirectional photodetector according to  claim 1 , wherein said conical member has a round tip end.  
   
   
       4 . The omnidirectional photodetector according to  claim 1 , wherein said conical member has an apex angle of about 70 degrees.  
   
   
       5 . The omnidirectional photodetector according to  claim 1 , wherein said prism is made of a light-transmissive synthetic resin.  
   
   
       6 . The omnidirectional photodetector according to  claim 5 , wherein said light-transmissive synthetic resin is acrylic resin.  
   
   
       7 . An infrared receiver for receiving an infrared radiation beam representing a signal which is modulated with encoded control data, comprising: 
 a prism having a columnar body and a conical member disposed on an end of said columnar body and having a cross-sectional area that is progressively smaller toward a tip end of said conical member, said conical member having a conical surface as an outer circumferential surface thereof providing a reflecting surface for reflecting an infrared radiation beam applied from an external source to said conical surface into said columnar body;    a light-detecting device disposed at an opposite end of said columnar body, for detecting the infrared radiation beam reflected by said reflecting surface and outputting a signal represented by said infrared radiation beam;    amplifying means for amplifying the signal output from said light-detecting device; and    decoding means for demodulating and decoding the detected signal amplified by said amplifying means, into control data, and outputting the control data.    
   
   
       8 . The infrared receiver according to  claim 7 , further comprising: 
 interface means for converting the control data output from said decoding means into USB data and outputting said USB data.    
   
   
       9 . The infrared receiver according to  claim 8 , for being connected to a computer through said interface means, wherein said control data comprises control data for controlling an application program installed in said computer.  
   
   
       10 . The infrared receiver according to  claim 9 , wherein said application program comprises a program for displaying images on a display unit of said computer by switching between pages in a slide show mode, and said control data comprises control data for enabling said computer to scroll the images displayed on said display unit page by page and/or to display the images in uniform black or uniform white on said display unit.  
   
   
       11 . The infrared receiver according to  claim 7 , further comprising: 
 a casing housing said prism and said light-detecting device therein with said conical member being exposed; and    attachment means mounted on said casing for disengageably engaging a plate-like member;    said attachment means comprising: 
 a first arm and a second arm which are pivotally coupled to said casing so as to be angularly movable toward and away from each other; and  
 biasing means for normally biasing said first arm and said second arm to move toward each other;  
 wherein said first arm and said second arm grip said plate-like member when said first arm and said second arm are angularly moved toward each other.